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<topic id="topic1" xml:lang="en"><title id="gg143896">pg_compression</title><body><p>The <codeph>pg_compression</codeph> system catalog table describes the
compression methods available.</p><table id="gg143898"><title>pg_catalog.pg_compression</title><tgroup cols="5"><colspec colnum="1" colname="col1" colwidth="93pt"/><colspec colnum="2" colname="col2" colwidth="64pt"/><colspec colnum="3" colname="col3" colwidth="85pt"/><colspec colnum="4" colname="col4" colwidth="57pt"/><colspec colnum="5" colname="col5" colwidth="147pt"/><thead><row><entry colname="col1">column</entry><entry colname="col2">type</entry><entry colname="col3">modifers</entry><entry colname="col4">storage</entry><entry colname="col5">description</entry></row></thead><tbody><row><entry colname="col1"><codeph>compname</codeph></entry><entry colname="col2">name</entry><entry colname="col3">not null</entry><entry colname="col4">plain</entry><entry colname="col5">Name of the compression</entry></row><row><entry colname="col1"><codeph>compconstructor</codeph></entry><entry colname="col2">regproc</entry><entry colname="col3">not null</entry><entry colname="col4">plain</entry><entry colname="col5">Name of compression constructor</entry></row><row><entry colname="col1"><codeph>compdestructor</codeph></entry><entry colname="col2">regproc</entry><entry colname="col3">not null</entry><entry colname="col4">plain</entry><entry colname="col5">Name of compression destructor</entry></row><row><entry colname="col1"><codeph>compcompressor</codeph></entry><entry colname="col2">regproc</entry><entry colname="col3">not null</entry><entry colname="col4">plain</entry><entry colname="col5">Name of the compressor</entry></row><row><entry colname="col1"><codeph>compdecompressor</codeph></entry><entry colname="col2">regproc</entry><entry colname="col3">not null</entry><entry colname="col4">plain</entry><entry colname="col5">Name of the decompressor</entry></row><row><entry colname="col1"><codeph>compvalidator</codeph></entry><entry colname="col2">regproc</entry><entry colname="col3">not null</entry><entry colname="col4">plain</entry><entry colname="col5">Name of the compression validator</entry></row><row><entry colname="col1"><codeph>compowner</codeph></entry><entry colname="col2">oid</entry><entry colname="col3">not null</entry><entry colname="col4">plain</entry><entry colname="col5">oid from pg_authid</entry></row></tbody></tgroup></table></body></topic>
